What Is A Butterfly Valve?
A butterfly valve is a quarter-turn valve that is used to regulate flow. A metal disc in the body of the valve is placed perpendicular to the flow in the closed position, and rotated one quarter-turn to be parallel to the flow in the fully opened position. Halfway rotations allow the regulation of liquid flow. They are often used in agricultural and water or wastewater treatment applications and are one of the most common and well-known valve types.
Advantages of a Butterfly Valve
Butterfly valves are similar to ball valves but have several more advantages. They are small and, when triggered pneumatically, open and close very swiftly. The disc is lighter than a ball, and the valve requires less structural support than a ball valve of comparable diameter. Butterfly valves are very precise, which makes them advantageous in industrial applications. They are quite reliable and require very little maintenance.
Disadvantages of a Butterfly Valve
One disadvantage of butterfly valves is that some portion of the disc is always presented to the flow, even when fully opened. The use of a butterfly valve therefore always results in a pressure switch across the valve, regardless of the setting.
Butterfly Valves Operating Electronically, Pneumatically or Manually
Butterfly valves can be configured to operate manually, electronically or pneumatically. Pneumatic valves operate most rapidly. Electronic valves require a signal to the gearbox to open or close, while pneumatic valves can be either single or double-actuated. A single-actuated valve is usually set up to require a signal to open with a failsafe, meaning that when power is lost the valve springs back to a fully closed position. Double-actuated pneumatic valves are not spring loaded and require a signal both to open and to close.
Automated pneumatic butterfly valves are both durable and reliable. Diminished wear increases the valve life cycle, which reduces operating costs otherwise lost in working hours to maintain the valves.
In the pharmaceutical, chemical and food industry a butterfly valve is used to interrupt product flow (solid, liquid, gas) within the process. The valves used in these industries are usually manufactured according cGMP guidelines (current good manufacturing practise). Butterfly valves largely replaced ball valves in many industries particularly petroleum due to lower cost and ease of installation, but pipelines containing butterfly valves cannot be ‘pigged’ for cleaning.
D&D Valve and Engineering Supply, established over 30 years ago, are importers, suppliers and distributors of a wide range of valves, pipes, pipe fittings, flanges and gaskets, covering a wide range of applications to the general and mining industry.With D&D Valve’s experience and knowledge in this market, they can offer technical advice for most applications. D&D Valve have also built up a reputation as being a one-stop engineering supply store.